Lucian m



(No Model.)

L. M. FOSTER.

BORING BIT OB. AUGER. No. 324,763. Patented Au He. 2. Wi bwlsses: Ila e72 for: g @flMw/r LUCIANMfbSTER,

g 1y Wm ML v b [ZZornqy N, PETERS. Photo-Lithographer. Washi nnnnnn .C-

LUOIAN M. FOSTER, OF TROY, NEW YORK, ASSIGNOR TO SAMUEL FOSTER AND JOHN H. REYNOLDS, OF SAME PLACE.

BORlNG -BIT OR AUGER.

SPECIFICATION forming part of Letters Patent No. 324,763, dated August 18, 1885.

Application filed May 18, 1885. (No model.)

.To all whom it may concern:

Be it known that I, LUOIAN M. FOSTER, of Troy, in the county of Rensselaer and State of New York, have invented a new and useful Improvement in Boring-Bits and Angers, of

which the following is a specification.

My invention relates to improvements in tools for boring wood and other similar material; and it consists of a tool having an angular cutting'end and a hollow body formed of a metallic ribbon wound spirally and provided with a cutting-edge that is adapted to effect the truing out of the hole to the entire depth of the bore.

I5 The object of my invention is to provide a reliable tool for boring a smooth and true hole, which will not become heated in performing its work while driven at a high rate of speed. This object I attain by means of the construction illustrated in the accompanying drawings, which, being herein referred to, form part of this specification, and in which Figure l is aside elevation of my improved boring-bit adapted to boring cylindrical holes;

2 Fig. 2, a crosssection of the same at the line a: m,- Fig. 3, a side elevation of my boring-bit adapted to boring tapering holes; and Fig. 4., a cross-section at the line y y of Fig. 3.

As represented in the drawings, A is the 0 boring-bit, having at its lower extremity a hollow coniformpenetrating end or cuttingpod, (1, whose foremost radial line is sharpened to produce a cutting-edge, as shown in Figs. 2 and 4. Said cutting-pod is made integral with the spirally-wound metallic ribbon b, which, when made in the form shown in Fig. 1 and revolved on its longitudinal axis, will produce a figure having acylindrical outline, as indicated by dotted lines in said figure;

but when made in the form shown in Fig. 3, in which the spiral ribbon expands regularly from the bottom to the top, and revolved, as above described, a tapering figure will be produced, as indicated by the dotted line-s in the last-named figure. The said ribbon may be 5 produced from a solid body by boring out its core and cutting or milling out the unnecessary portions of the shell; or by milling, from a solid body, the core and unrequired portions of its exterior surface 5 or by spirally winding 0 a flat ribbon around a mandrel, either cylindrical or tapered, as occasion requires. The advancing edge I) of the ribbon is sharpened along the entire length of the spiral line, so as to smooth and true out the hole made normally by the cutting-pod a. The ribbon b is either made integrally with or fastened to a shank, c, or other stem, by which the tool is fixed in a stock, handle, or other device, so as to be rotated at any required rate of speed.

One of the advantages of this form of tool is that, by reason of its hollow body and spiral twist, it removes the chips so rapidly that it can be rotated at a high rate of speed and fed in very rapidly without the tool becoming heated, and the hole is bored out smooth and true in a very short space of time.

I claim as my invention- A boring-tool composed of a cutting-pod, a, and a spirally-wound ribbon, 1), without a cen- 7o tral core, the said ribbon being provided with a sharp cutting-edge on the entire length of its foremost spiral line, as and for the purpose herein specified.

LUCIAN M. FOSTER.

XVitnesses:

J. H. REYNoLDs, WM. H. Low. 

